Latissimus Dorsi, Posterior View

Description

Spanning the posterolateral trunk, the paired latissimus dorsi forms a broad, fan-shaped sheet arising from the lower thoracic spinous processes and thoracolumbar fascia, with inferior fibers blending toward the posterior iliac crest. Its muscular belly sweeps superolaterally, narrowing as it approaches the axilla to become a tendon that courses anterior to teres major and inserts on the floor of the intertubercular sulcus of the humerus. Along the superior border, the latissimus dorsi meets the lower fibers of trapezius near the midline, while laterally it frames the posterior axillary fold adjacent to the posterior deltoid contour. Posterior emphasis on the thoracolumbar fascia makes this view useful for teaching force transmission between trunk and upper limb, since the latissimus dorsi shares fascial continuity with the erector spinae aponeurosis and indirectly with the gluteal fascia. Surgeons rely on this surface anatomy when raising a pedicled latissimus dorsi flap for breast or chest wall reconstruction, tracking the thoracodorsal vessels and nerve as they enter the deep surface near the posterior axillary fold to avoid denervation and bulk loss. Sports medicine applications are equally direct: strain or tendinopathy near the humeral insertion can mimic rotator cuff pain and is often provoked by climbing, swimming, or overhead throwing with resisted shoulder adduction and extension. Big muscle. Commonly overlooked. Use this artwork for gross anatomy and kinesiology modules on shoulder extension, adduction, and internal rotation, or in surgical atlases outlining posterior axillary fold landmarks, latissimus harvest planes, and donor site closure considerations. It also reads well in rehabilitation handouts where clinicians need to explain referred pain patterns and the relationship of latissimus dorsi to scapulothoracic motion and lumbar load transfer. Anatomical accuracy verified by SciePro's Medical Advisory Board.